Magneto-telephone



(No M a 1. 1

f e A. STROMBBRG su A. CARLSON.

MAGNBTO TBAEPHONB.

No. 521,188. l vIJ'JNl'AaIl'led June 12, 1894.

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Y WASKXNGYON. DA C UNITED STATES PATENT EEICE.

ALFRED STROMBERG AND ANDREW CARLSON, OFCI-IICAGO, ILLINOIS.

MAGNETO-TELEPHONE.

SPECIFICATION forming part of Letters Patent No. 5121,188, dated June12, 1894.

Application led March 9, 1894:.

.To @ZZ whom it may concern:

Be it known that we, ALFRED STROMBERG and ANDREW CARLSON, citizens ofthe United States, residing at Chicago, in the county of Cook and Stateof Illinois, have invented a certain new and useful Improvement inMagneto-Telephones, (Case No. 13,) of which the following is a full,clear, concise, and exact description, reference being had to theaccompanying drawings, forming a part of this specification. v

Our invention relates to magneto telephones, and more particularly toimprovements in a combined telephone and magneto generator described inLetters Patent No. 504,636, and its object is to produce a moreeconomical construction and to provide means for preventing thediaphragm from getting out of adjustment.

ln the Letters Patent above referred to, isy

shown a magneto generator provided withv soft iron polar extensionsaround which the telephone coils are Wound, and opposite the ends ofwhich the diaphragm is located. Our invention herein contemplates thecheapening of this construction by constructing the magneto generator ofparallel disposed bar magnets and providing between the magnets at oneend, pole pieces, between which the armature is adapted to rotate. Thesoft iron polar extensions or cores may, in this construction, beprovided either upon the ends at which the pole pieces are provided, or,when more convenient, at the opposite ends. In the apparatus of saidLetters Patent the magneto generator is secured to the inside of awooden casing, while the metal casing which supports the diaphragm issecured to vthe outside of said wooden casing. A disadvantage arisingfrom this construction is that, since a layer of wood, which Variesconsiderably in thickness with changes of tempera` ture and moisture, isinterposed between the generator, upon which the core pieces are rigidlymounted, and the diaphragm support, any change of thickness of the layerof wood tends to throw the telephone out of adjustment. With thisobjection in view, our invention contemplates the mounting of thediaphragm support relatively to the gener- Serial No. 5031044. (Nomodel.)

ator upon which the core pieces are mounted so that the disadjustmentofthe telephone will be prevented.

Our invention contemplates further au improved adjustment for thediaphragm with means for locking the diaphragm support in its adj ustedposition, as will herein more fully be described. v

XVe will describe our invention in connection with the accompanyingdrawings, in which- Figure 1 is an elevation, partially in section, of acombined telephone and generator constructed after the manner of ourinvention. Fig. 2 is a view at right angles thereto. Fig. 3 is a viewshowing the soft iron cores mounted upon the ends of the bar magnetsbetween which the pole pieces are mounted. Fig. 4 is a plan view of thetelephone transmitter. Like letters refer to like parts in the severalfigures.

Referring to Figs. 1 and 2, a number of bar magnets a a', situated sideby side are maintained parallel to a second series b b by properdistance pieces. The number of the magnets employed may be determined bythe desired strength of magnetic field. Between the ends of the magnetsare mounted the pole pieces c and c', which may be of cast iron, andsecured one to each 0f the series of magnets. Between the ends of thepole pieces are placed distance pieces d d', of brass or othernonmagnetic material. Between the pole pieces c and c the armature e isadapted to be rotated. To the opposite ends of the magnetsv are securedthe pieces f f preferably of cast iron, the same being maintained at theproper distance apart by distance pieces g which may be of magnetic orof non-magnetic material as it is desired to utilize the whole or a partof the magnetic field for the magneto telephone. Mounted upon the endsof the castings f f is the metallic casing h, upon which the diaphragmis adapted to be supported. The

Y soft iron polar extensions k 7c are located with their ends a shortdistance apart and separated from the bottom o f casing h bynon-magnetic filling pieces h', the said polar extensions beingmaintained in position by screws Z Z of magnetic material, which passthrough the casing h and fillers 7i and extend into the cast iron piecesff. The polar extensions are thus magnetically connected with the barmagnets. The telephone coils 'ni m are placed over 'the polar extenfsions and the diaphragm n properly mounted. If the distance pieces g benon-magnetic, all of the lines of force of the magnets, except such asmay leak across the air space, will thread the polar extensions and thediaphragm, and the field `of the telephone will be ot" maximum strength.Should a iield ot' less strength be desired, the distance pieces g maybe made of magnetic material, or a magnetic shunt of any other form maybe provided about the polar extensions.

In Fig. `3 the polar extensions are shown as mounted upon the same endsof the magnets as are the pole pieces, a yoke piece o being providedbetween the opposite ends to complete tlie magnetic circuit.

port is inetallically connected with the bar magnets as well as the corepieces, and that,

in consequence, changes of temperature or moisture will not throw thediaphragm out of adjustment as would be the case were the wooden casinginterposed between the dia phragm support and the magnets as in thelpatent heretofore referred to. In the claims z the expressionmetallically mounted is 1 used in the sense that no material capable ofexpansion under changes of temperature and moisture is interposedbetween the diaphragm support and the magnets.

To provide for adj ustment of the diaphragm toward and from the polarextensions or cores k 7c', a cap p is provided carrying a mouthpiece p',the cap being provided with an internally threaded flange adapted to bescrewed upon the casing h. may be secured to the under side of the capby screws p2, Fig. 3, or by a threaded ring p3, Fig. 1, between whichand the under surface of the cap the diaphragm may be clamped.

The diaphragm may be readily adjusted to i any height by rotating thecap about its cenf tral axis, and may be locked in its Vadjustedposition by means of the internally threaded ring p4 `which is adaptedto be screwed against the ange provided upon the cap.

It is "evident that our invention is susceptible of modilications, andwe `do not, therefore, desire to limit ourselves to particulars, p

but

claim as new, and desire to secure by Letters Patent, is

1. The combination with permanent bar magnets, of pole pieces mountedupon the ends of said magnets, between which 'the armature is adapted torotate, soft iron cores extending from the poles of said magnets, theends thereof being in proximity and surrounded by telephone coils, and adiaphragm The diaphragm mounted opposite the ends of said cores,substantially as described.

2. The combination with permanent bar magnets, of pole pieces mounteduponthc ends of said magnets, between which the armature is adapted torotate, soft iron cores extending from the ends of said magnets oppositethose upon which said pole pieces are mounted, the ends of said coreslying in proximity and surrounded by telephone coils, and a diaphragmmounted opposite the ends of said cores, substantially as described.

`3. The combination with permanent bar magnets, of pole pieces mountedupon the ends of said magnets, between which the armature is adapted torotate, soft iron cores extending from the ends of said magnets oppositethose upon which said pole pieces are mounted, the ends ot said `coreslying in proximity and surrounded by telephone coils, a diaphragmmounted opposite the ends of said cores, and a bar of .magnetic materialIt will be noted that the diaphragm supconnecting the ends of said barmagnets upon which said soft iron cores are mounted, thereby providing amagnetic shunt about tlic same, substantially as described.

4. The combination with a permanent magnet, of a casing supporting thediaphragm and metallicaily mounted upon said magnet, soft iron coresextending from the poles of said magnet through the bottom of saidcasing, the ends thereof being approached and situated opposite saiddiaphragm, `and telephone coils provided on said cores, substantially asdescribed.

5. The combination with the straight bar magnets a Zi, of the polepieces c c' mounted upon the ends of said magnets, the cast iron piecesf f mounted upon the opposite ends of said magnets, the casing ordiaphragm support h mounted upon said castiron pieces ff", the soft ironcores 7c 7c' mounted upon said pieces f f', and the diaphragm usupported upon said diaphragm support 71. and mounted opposite theapproached ends ot said soft iron cores 7c 7c', substantially asdcscribed.

G. The combination with a cap, of a diaphragm resting against 'the underside of the same, a threaded ring adapted to be screwed within said capagainst said diaphragm, and a casingA provided "with threads adapted toengage threads upon said cap, substantially as described.

`7. The combination with a cap, of a diaphragm resting against the underside of the Having described our invention, what we.

same, a threaded ringadapted to be screwed within said cap against saiddiaphragm, a casing provided with threads adapted to engage threads uponsaid cap whereby the diaphragm may be adj usted and a threaded ringadapted to be screwed upon said casing and against said cap to lock thesame in its ad- ]usted position, substantially as described.

8. The combination with a cap provided with an internally threadedflange, of a IIO threaded ring adapted to be screwed upon In witnesswhereof We hereunto subscribe said threaded flange, adiaphragm adaptedto our names this 7 th day of March, A. D. 1894. I'o be clamped betweenthe under side of said ALFRED STROMBERG. cap and sald ring` and a casingprovided with.

5 a thread adapted to engage a thread upon ANDREW CARLSON said cap;whereby said diaphragm may be Witnesses: adj ustabiy raised and lowered,substantially GEORGE L. CRAGG, as described. GEORGE S. BUELL.

